Flash light circuitry may be used to generate a flash of light. This may be used in photography to achieve an instantaneous illumination of the field of view.
A problem can arise when close objects reflect the flash of light into the camera sensor or material imperfections in transparent material cause light diffusion into the camera sensor. This may result in over-exposure of those objects in a captured image, non-wanted stray light effects or in an image of the flash itself being captured.
This problem is, for example, experienced if one attempts to capture an image through a glass window using flash photography.